]> www.infradead.org Git - users/jedix/linux-maple.git/commit
drm/repaper: fix integer overflows in repeat functions
authorNikita Zhandarovich <n.zhandarovich@fintech.ru>
Thu, 16 Jan 2025 13:48:01 +0000 (05:48 -0800)
committerAlex Lanzano <lanzano.alex@gmail.com>
Tue, 25 Feb 2025 00:43:23 +0000 (19:43 -0500)
commit4d098000ac193f359e6b8ca4801dbdbd6a27b41f
treefdeb986599a163349c198ffb9fa5eda2c89963f0
parented531feda7852de0aa702fbe3d23a0f743ccc77b
drm/repaper: fix integer overflows in repeat functions

There are conditions, albeit somewhat unlikely, under which right hand
expressions, calculating the end of time period in functions like
repaper_frame_fixed_repeat(), may overflow.

For instance, if 'factor10x' in repaper_get_temperature() is high
enough (170), as is 'epd->stage_time' in repaper_probe(), then the
resulting value of 'end' will not fit in unsigned int expression.

Mitigate this by casting 'epd->factored_stage_time' to wider type before
any multiplication is done.

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: 3589211e9b03 ("drm/tinydrm: Add RePaper e-ink driver")
Cc: stable@vger.kernel.org
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Alex Lanzano <lanzano.alex@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250116134801.22067-1-n.zhandarovich@fintech.ru
drivers/gpu/drm/tiny/repaper.c